Enhanced photoluminescence

ABSTRACT

Described embodiments include a plasmonic apparatus and method. The plasmonic apparatus includes a substrate having a first negative-permittivity layer comprising a first plasmonic surface. The plasmonic apparatus includes a plasmonic nanoparticle having a base with a second negative-permittivity layer comprising a second plasmonic surface. The plasmonic apparatus includes a dielectric-filled gap between the first plasmonic surface and the second plasmonic surface. The plasmonic apparatus includes a plasmonic cavity created by an assembly of the first plasmonic surface, the second plasmonic surface, and the dielectric-filled gap, and having a spectrally separated first fundamental resonant cavity wavelength λ 1  and second fundamental resonant cavity wavelength λ 2 . The plasmonic apparatus includes a plurality of fluorescent particles located in the dielectric-filled gap. Each fluorescent particle of the plurality of fluorescent particles having an absorption spectrum including the first fundamental resonant cavity wavelength λ 1  and an emission spectrum including the second fundamental resonant cavity wavelength λ 2 .

If an Application Data Sheet (ADS) has been filed on the filing date ofthis application, it is incorporated by reference herein. Anyapplications claimed on the ADS for priority under 35 U.S.C. §§119, 120,121, or 365(c), and any and all parent, grandparent, great-grandparent,etc. applications of such applications, are also incorporated byreference, including any priority claims made in those applications andany material incorporated by reference, to the extent such subjectmatter is not inconsistent herewith.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of the earliest availableeffective filing date(s) from the following listed application(s) (the“Priority Applications”), if any, listed below (e.g., claims earliestavailable priority dates for other than provisional patent applicationsor claims benefits under 35 USC §119(e) for provisional patentapplications, for any and all parent, grandparent, great-grandparent,etc. applications of the Priority Application(s)).

Priority Applications

NONE

If the listings of applications provided above are inconsistent with thelistings provided via an ADS, it is the intent of the Applicant to claimpriority to each application that appears in the DomesticBenefit/National Stage Information section of the ADS and to eachapplication that appears in the Priority Applications section of thisapplication.

All subject matter of the Priority Applications and of any and allapplications related to the Priority Applications by priority claims(directly or indirectly), including any priority claims made and subjectmatter incorporated by reference therein as of the filing date of theinstant application, is incorporated herein by reference to the extentsuch subject matter is not inconsistent herewith.

SUMMARY

For example, and without limitation, an embodiment of the subject matterdescribed herein includes a plasmonic apparatus. The plasmonic apparatusincludes a substrate having a first negative-permittivity layercomprising a first plasmonic surface. The plasmonic apparatus includes aplasmonic nanoparticle having a base with a second negative-permittivitylayer comprising a second plasmonic surface. The plasmonic apparatusincludes a dielectric-filled gap between the first plasmonic surface andthe second plasmonic surface. The plasmonic apparatus includes aplasmonic cavity created by an assembly of the first plasmonic surface,the second plasmonic surface, and the dielectric-filed gap, and having aspectrally separated first fundamental resonant cavity wavelength λ₁ andsecond fundamental resonant cavity wavelength λ₂. The plasmonicapparatus includes a plurality of fluorescent particles located in thedielectric-filled gap. Each fluorescent particle of the plurality offluorescent particles having an absorption spectrum including the firstfundamental resonant cavity wavelength λ₁ and an emission spectrumincluding the second fundamental resonant cavity wavelength λ₂.

For example, and without limitation, an embodiment of the subject matterdescribed herein includes a plasmonic apparatus. The plasmonic apparatusincludes a substrate having a first negative-permittivity layercomprising a first plasmonic surface. The plasmonic apparatus includes aplasmonic nanoparticle having a base with a second negative-permittivitylayer comprising a second plasmonic surface. The plasmonic apparatusincludes a dielectric-filled gap between the first plasmonic surface andthe second plasmonic surface. The plasmonic apparatus includes aplasmonic cavity created by an assembly of the first plasmonic surface,the second plasmonic surface, and the dielectric-filed gap, and having aspectrally separated first fundamental resonant cavity wavelength λ₁ andsecond resonant cavity wavelength λ₂ that is a 3^(rd) harmonic of thefirst fundamental resonant cavity wavelength λ₁. The plasmonic apparatusincludes a plurality of fluorescent particles located in thedielectric-filled gap, each fluorescent particle of the plurality offluorescent particles having an absorption spectrum including the firstfundamental resonant cavity wavelength λ₁ and a 3^(rd) harmonicnonlinearity with an emission spectrum including the second resonantcavity wavelength λ₂.

For example, and without limitation, an embodiment of the subject matterdescribed herein includes a method. The method includes directing afirst electromagnetic beam that includes a first wavelength λ₁ at aplasmonic apparatus. The method includes emitting a secondelectromagnetic beam at a second wavelength λ₂ from the plasmonicapparatus, the second electromagnetic beam having a higher quantumenergy level than the first electromagnetic beam. The plasmonicapparatus includes a substrate having a first negative-permittivitylayer comprising a first plasmonic surface. The plasmonic apparatusincludes a plasmonic nanoparticle having a base with a secondnegative-permittivity layer comprising a second plasmonic surface. Theplasmonic apparatus includes a dielectric-filled gap between the firstplasmonic surface and the second plasmonic surface. The plasmonicapparatus includes a plasmonic cavity created by an assembly of thefirst plasmonic surface, the second plasmonic surface, and thedielectric-filed gap, and having a spectrally separated firstfundamental resonant cavity wavelength λ₁ and second fundamentalresonant cavity wavelength λ₂. The plasmonic apparatus includes aplurality of fluorescent particles located in the dielectric-filled gap,each fluorescent particle of the plurality of fluorescent particleshaving an absorption spectrum including the first fundamental resonantcavity wavelength λ₁ and an emission spectrum including the secondfundamental resonant cavity wavelength λ₂.

The foregoing summary is illustrative only and is not intended to be inany way limiting. In addition to the illustrative aspects, embodiments,and features described above, further aspects, embodiments, and featureswill become apparent by reference to the drawings and the followingdetailed description.

The foregoing summary is illustrative only and is not intended to be inany way limiting. In addition to the illustrative aspects, embodiments,and features described above, further aspects, embodiments, and featureswill become apparent by reference to the drawings and the followingdetailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of an example plasmonic apparatus;

FIG. 2 illustrates a side view of the example plasmonic apparatus;

FIG. 3 illustrates an example operational flow;

FIG. 4 illustrates an example gain system;

FIG. 5 illustrates an example operational flow for amplifyingelectromagnetic waves;

FIG. 6 illustrates an example plasmonic nanoparticle dimer;

FIG. 7 illustrates an environment that includes gain system; and

FIG. 8 illustrates an example operational flow. After a start operation,the operational flow includes a photoexcitation operation.

DETAILED DESCRIPTION

This application makes reference to technologies described more fully inUnited States Patent Application No. To be assigned, entitled ENHANCEDPHOTOLUMINESCENCE, naming Gleb M. Akselrod, Roderick A. Hyde, Muriel Y.Ishikawa, Jordin T. Kare, Maiken H. Mikkelsen, Tony S. Pan, David R.Smith, Clarence T. Tegreene, Yaroslav A. Urzhumov, Charles Whitmer,Lowell L. Wood, Jr., and Victoria Y. H. Wood as inventors, filed on Jun.27, 2016, is related to the present application. That application isincorporated by reference herein, including any subject matter includedby reference in that application.

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof. In the drawings,similar symbols typically identify similar components, unless contextdictates otherwise. The illustrative embodiments described in thedetailed description, drawings, and claims are not meant to be limiting.Other embodiments may be utilized, and other changes may be made,without departing from the spirit or scope of the subject matterpresented here.

Those having skill in the art will recognize that the state of the arthas progressed to the point where there is little distinction leftbetween hardware, software, and/or firmware implementations of aspectsof systems; the use of hardware, software, and/or firmware is generally(but not always, in that in certain contexts the choice between hardwareand software can become significant) a design choice representing costvs. efficiency tradeoffs. Those having skill in the art will appreciatethat there are various implementations by which processes and/or systemsand/or other technologies described herein can be effected (e.g.,hardware, software, and/or firmware), and that the preferredimplementation will vary with the context in which the processes and/orsystems and/or other technologies are deployed. For example, if animplementer determines that speed and accuracy are paramount, theimplementer may opt for a mainly hardware and/or firmwareimplementation; alternatively, if flexibility is paramount, theimplementer may opt for a mainly software implementation; or, yet againalternatively, the implementer may opt for some combination of hardware,software, and/or firmware. Hence, there are several possibleimplementations by which the processes and/or devices and/or othertechnologies described herein may be effected, none of which isinherently superior to the other in that any implementation to beutilized is a choice dependent upon the context in which theimplementation will be deployed and the specific concerns (e.g., speed,flexibility, or predictability) of the implementer, any of which mayvary. Those skilled in the art will recognize that optical aspects ofimplementations will typically employ optically-oriented hardware,software, and or firmware.

In some implementations described herein, logic and similarimplementations may include software or other control structuressuitable to implement an operation. Electronic circuitry, for example,may manifest one or more paths of electrical current constructed andarranged to implement various logic functions as described herein. Insome implementations, one or more media are configured to bear adevice-detectable implementation if such media hold or transmit aspecial-purpose device instruction set operable to perform as describedherein. In some variants, for example, this may manifest as an update orother modification of existing software or firmware, or of gate arraysor other programmable hardware, such as by performing a reception of ora transmission of one or more instructions in relation to one or moreoperations described herein. Alternatively or additionally, in somevariants, an implementation may include special-purpose hardware,software, firmware components, and/or general-purpose componentsexecuting or otherwise invoking special-purpose components.Specifications or other implementations may be transmitted by one ormore instances of tangible transmission media as described herein,optionally by packet transmission or otherwise by passing throughdistributed media at various times.

Alternatively or additionally, implementations may include executing aspecial-purpose instruction sequence or otherwise invoking circuitry forenabling, triggering, coordinating, requesting, or otherwise causing oneor more occurrences of any functional operations described below. Insome variants, operational or other logical descriptions herein may beexpressed directly as source code and compiled or otherwise invoked asan executable instruction sequence. In some contexts, for example, C++or other code sequences can be compiled directly or otherwiseimplemented in high-level descriptor languages (e.g., alogic-synthesizable language, a hardware description language, ahardware design simulation, and/or other such similar mode(s) ofexpression). Alternatively or additionally, some or all of the logicalexpression may be manifested as a Verilog-type hardware description orother circuitry model before physical implementation in hardware,especially for basic operations or timing-critical applications. Thoseskilled in the art will recognize how to obtain, configure, and optimizesuitable transmission or computational elements, material supplies,actuators, or other common structures in light of these teachings.

FIG. 1 illustrates a perspective view of an example plasmonic apparatus100. FIG. 2 illustrates a side view of the example plasmonic apparatus100. The plasmonic apparatus includes a substrate 110 having a firstnegative-permittivity layer 112 comprising a first plasmonic surface114. The plasmonic apparatus includes a plasmonic nanoparticle 120having a base 122 with a second negative-permittivity layer 124comprising a second plasmonic surface 126. The plasmonic apparatusincludes a dielectric-filled gap 130 between the first plasmonic surfaceand the second plasmonic surface. A plasmonic cavity 142 created by anassembly 140 of the first plasmonic surface, the second plasmonicsurface, and the dielectric-filled gap, and having a spectrallyseparated first fundamental resonant cavity wavelength λ₁ and secondfundamental resonant cavity wavelength λ₂. The plasmonic apparatusincludes a plurality of fluorescent particles 150 located in thedielectric-filled gap 130. Each fluorescent particle of the plurality offluorescent particles has an absorption spectrum including the firstfundamental resonant cavity wavelength λ₁ and an emission spectrumincluding the second fundamental resonant cavity wavelength λ₂.

In an embodiment of the plasmonic cavity 142, the first fundamentalresonant cavity wavelength λ₁ is a function of a first characteristic ofthe plasmonic nanoparticle 120 and the second fundamental resonantcavity wavelength λ₂is a function of a second characteristic of theplasmonic nanoparticle. In an embodiment of the plasmonic cavity, thefirst fundamental resonant cavity wavelength λ₁ is a function of a firststructural characteristic of the plasmonic nanoparticle and the secondfundamental resonant cavity wavelength λ₂ is a function of a secondstructural characteristic of the plasmonic nanoparticle. In anembodiment of the plasmonic cavity, the first fundamental resonantcavity wavelength λ₁ is a function of a first dimensional characteristicof the plasmonic nanoparticle and the second fundamental resonant cavitywavelength λ₂ is a function of a second dimensional characteristic ofthe plasmonic nanoparticle. In an embodiment of the plasmonic cavity,the first fundamental resonant cavity wavelength λ₁ is a function of afirst side dimension 128 of the non-square rectangular base 122 of theplasmonic nanoparticle and the second fundamental resonant cavitywavelength λ₂is a function of a second side dimension 129 of thenon-square rectangular base of the plasmonic nanoparticle. For example,a non-square rectangular base of the plasmonic nanoparticle may be 40×10nm, or 40×20 nm.

In an embodiment of the plasmonic nanoparticle 120, the base 122 of theplasmonic nanoparticle is at least substantially conformal to the firstplasmonic surface 114. In an embodiment of the plasmonic nanoparticle,the base of the plasmonic nanoparticle is at least substantially planar.In an embodiment of the plasmonic nanoparticle, the base of theplasmonic nanoparticle has a major side 128, and a minor side 129shorter than the major side. In an embodiment of the plasmonicnanoparticle, the major side corresponds to a base dimension in a firstdirection and the minor side corresponds to a shorter base dimension ina non-aligned direction. In an embodiment of the plasmonic nanoparticle,the non-aligned direction is at least substantially perpendicular to thefirst direction. In an embodiment, the plasmonic nanoparticle includesat least two joined or proximate plasmonic nanoparticles forming thebase with their combined second negative-permittivity layers 124comprising the second plasmonic surface 126. For example, the at leasttwo plasmonic nanoparticles may be arranged in a 1×2, 2×5, 3×4, or 5×9configuration. In an embodiment of the plasmonic nanoparticle, the atleast two joined or proximate plasmonic nanoparticles form a non-squarerectangular base with a combined second negative-permittivity layercomprising a second plasmonic surface.

In an embodiment of the plasmonic nanoparticle 120, the plasmonicnanoparticle includes a nanorod having a non-square rectangular base 122with the second negative-permittivity layer 124. In an embodiment of theplasmonic nanoparticle, the base of the plasmonic nanoparticle includesat least one of a rectangular, an ellipsoidal, or a triangular shape. Inan embodiment of the plasmonic nanoparticle, the base of the plasmonicnanoparticle has an elongated shape. In an embodiment of the plasmonicnanoparticle, the base of the plasmonic nanoparticle has an arbitraryshape. In an embodiment of the plasmonic nanoparticle, the base of theplasmonic nanoparticle has a major side 128 length ranging between10-10000 nm. In an embodiment of the plasmonic nanoparticle, the base ofthe plasmonic nanoparticle has a major side length between about 100 andabout 1000 nm. In an embodiment of the plasmonic nanoparticle, the baseof the plasmonic nanoparticle has a major side length ranging between500 and 7000 nm.

In an embodiment, the plasmonic cavity 142 has a spectrally separatedfirst spectral resonant envelope that includes the first fundamentalresonant wavelength λ₁ and a second spectral resonant envelope thatincludes the second fundamental resonant wavelength λ₂. In anembodiment, the first spectral resonant envelope and the second spectralresonant envelope are substantially non-overlapping. In an embodiment,the first fundamental resonant wavelength λ₁ and second fundamentalresonant wavelength λ₂of the plasmonic cavity are both in theultraviolet spectrum. In an embodiment, the first fundamental resonantwavelength λ₁ is in the ultraviolet spectrum and second fundamentalresonant wavelength λ₂ of the plasmonic cavity is in the visible lightspectrum. In an embodiment, the first fundamental resonant wavelength λ₁is in the ultraviolet spectrum and second fundamental resonantwavelength λ₂of the plasmonic cavity is in the infrared spectrum. In anembodiment, the first fundamental resonant wavelength λ₁ and secondfundamental resonant wavelength λ₂ of the plasmonic cavity are both inthe visible light spectrum. In an embodiment, the first fundamentalresonant wavelength λ₁ is in the visible light spectrum and secondfundamental resonant wavelength λ₂of the plasmonic cavity is in theinfrared spectrum. In an embodiment, the first fundamental resonantwavelength λ₁ and second fundamental resonant wavelength λ₂ of theplasmonic cavity are both in the infrared spectrum. In an embodiment,the second fundamental resonant cavity wavelength λ₂ of the plasmonicnanoparticle is a harmonic of the first fundamental resonant cavitywavelength λ1 of the plasmonic cavity. In an embodiment, a ratio of thesecond fundamental resonant cavity wavelength λ₂to the first fundamentalresonant cavity wavelength λ₁ is an integer. In an embodiment, a ratioof the second fundamental resonant cavity wavelength λ₂ to the firstfundamental resonant cavity wavelength λ₁ is a rational number. Forexample, a rational number may include 3/2. In an embodiment, the secondfundamental resonant cavity wavelength λ₂is a 3^(rd) harmonic of thefirst fundamental resonant cavity wavelength λ₁ of the plasmonic cavity;and each fluorescent particle of the plurality of fluorescent particlesincludes a fluorescent particle with a 3^(rd) harmonic nonlinearityhaving an emission spectrum including the second fundamental resonantcavity wavelength λ₂. For example, a 3^(rd) order plasmonic nanoparticlemay be built by binding three plasmonic nanocubes together in a 1×3configuration. For example, doubly-resonant nanocubes may be assembled,such as with a non-square rectangular base, to generate 3rd harmoniclight from nonlinear materials. For example, a fluorescent material witha 3rd harmonic nonlinearity may be placed in the dialectic-filled gap130. The strong electric field components of the resonant field areexpected to generate 3rd harmonic light.

In an embodiment of the dielectric-filled gap 130, the dielectricincludes a non-linear optical material having a non-linear responseconfigured to enhance emission at the second fundamental resonant cavitywavelength λ₂.

In an embodiment, the plasmonic nanoparticle 120 includes a plurality ofplasmonic nanoparticles. Each plasmonic nanoparticle of the plurality ofplasmonic nanoparticles has a base 122 with the secondnegative-permittivity layer 124 comprising the second plasmonic surface126. In an embodiment, the plasmonic nanoparticle includes adoubly-resonant plasmonic nanoparticle. In an embodiment, at least oneof the plasmonic nanoparticle 120, the substrate 110, or the dielectric130 includes a nonlinear harmonic material. In this embodiment, thefirst fundamental resonant cavity wavelength λ₁ is a fundamentalresonant cavity wavelength of the nonlinear harmonic material and thesecond fundamental resonant cavity wavelength λ₂is a harmonic wavelengthof the fundamental resonant cavity wavelength.

In an embodiment of the plasmonic apparatus 100, the first plasmonicsurface 114 is coated with at least two fluorescent particles of theplurality of fluorescent particles 150. In an embodiment of theplasmonic apparatus, the second plasmonic surface 126 is coated with atleast two fluorescent particles of the plurality of fluorescentparticles.

In an embodiment of the plasmonic apparatus 100, the plurality offluorescent particles 150 are included in the dielectric-filled gap 130.In an embodiment, the dielectric-filed gap is a subwavelengthdielectric-filled gap. In an embodiment of the plasmonic apparatus, theplasmonic cavity 142 includes a plasmonic subwavelength cavity. In anembodiment of the plasmonic apparatus, the plasmonic cavity includes aplasmonic resonator.

In an embodiment of the plasmonic apparatus 100, the first plasmonicsurface 114 includes an adhesive configured to bond the first plasmonicsurface with the dielectric material of the dielectric-filled gap 130.In an embodiment of the plasmonic apparatus, the firstnegative-permittivity layer 112 has negative permittivity within adefined wavelength range. In an embodiment of the plasmonic apparatus,the second negative-permittivity layer 124 has negative permittivitywithin a defined wavelength range. In an embodiment of the plasmonicapparatus, the first negative-permittivity layer includes a metalliclayer. In an embodiment of the plasmonic apparatus, the firstnegative-permittivity layer includes a semi-metallic layer. In anembodiment of the plasmonic apparatus, the first negative-permittivitylayer includes a semiconductor layer. In an embodiment of the plasmonicapparatus, the first negative-permittivity layer includes a polaritonicdielectric layer. In an embodiment of the plasmonic apparatus, thesecond negative-permittivity layer at least partially covers the base ofthe plasmonic nanoparticle 120. In an embodiment of the plasmonicapparatus, the second negative-permittivity layer is formed over atleast the base 122 of the plasmonic nanoparticle. In an embodiment ofthe plasmonic apparatus, the second negative-permittivity layer includesa noble metal. In an embodiment of the plasmonic apparatus, the secondnegative-permittivity layer includes a metallic layer. In an embodimentof the plasmonic apparatus, the second negative-permittivity layerincludes a semimetal layer. In an embodiment of the plasmonic apparatus,the second negative-permittivity layer includes a semiconductor layer ora polaritonic dielectric layer. In an embodiment of the plasmonicapparatus, the second negative-permittivity layer includes an adhesiveconfigured to bond the second negative-permittivity layer with adielectric material of the dielectric-filled gap. In an embodiment ofthe plasmonic apparatus, the at least a portion of the dielectric-filledgap includes a dielectric coating applied to the first plasmonic surfaceof the substrate. In an embodiment of the plasmonic apparatus, the atleast a portion of the dielectric-filled gap includes a dielectriccoating applied to the second plasmonic surface of the plasmonicnanoparticle.

In an embodiment of the plasmonic apparatus 100, the dielectric-filledgap 130 is less than 5 nm thick 132. In an embodiment of the plasmonicapparatus, the dielectric-filled gap is less than 100 nm thick. In anembodiment of the plasmonic apparatus, the dielectric-filled gap is lessthan 50 nm thick. In an embodiment of the plasmonic apparatus, thedielectric-filled gap is less than 25 nm. In an embodiment of theplasmonic apparatus, the dielectric-filled gap is greater than 0 nm andless than 50 nm. In an embodiment of the plasmonic apparatus, thedielectric-filled gap is greater than 5 nm. In an embodiment of theplasmonic apparatus, the dielectric material of the dielectric-filledgap 130 includes a hard or soft dielectric material.

In an embodiment of the plasmonic apparatus 100, each fluorescentparticle of the plurality of fluorescent particles 150 has an absorptionpeak or maxima at a wavelength substantially aligned with the firstfundamental resonant cavity wavelength λ₁ and an emission peak or maximasubstantially aligned with the second fundamental resonant cavitywavelength λ₂. In an embodiment, each fluorescent particle of theplurality of fluorescent particles 150 has an absorption maxima at awavelength substantially aligned with the first fundamental resonantcavity wavelength λ₁ and an emission maxima substantially aligned withthe second fundamental resonant cavity wavelength λ₂. In an embodimentof the plasmonic apparatus, the plurality of fluorescent particles 150includes a plurality of fluorescent molecules. In an embodiment of theplasmonic apparatus, the plurality of fluorescent particles includes aplurality of fluorescent carbon particles. For example, fluorescentcarbon particles are described in N. Ranjan, Highly Fluorescent CarbonNanoparticles, U.S. Pat. Pub. No. 20120178099 (published Jul. 12, 2012).In an embodiment of the plasmonic apparatus, the plurality offluorescent particles includes a plurality of fluorescent semiconductorcrystals. In an embodiment of the plasmonic apparatus, the plurality offluorescent particles includes a plurality of fluorescent metalparticles. In an embodiment of the plasmonic apparatus, the plurality offluorescent particles includes a plurality of fluorescent quantum dots.In an embodiment of the plasmonic apparatus, the plurality offluorescent particles includes a plurality of fluorescent proteins. Forexample, fluorescent proteins may include green fluorescent proteins.

In an embodiment of the plasmonic apparatus 100, the substrate 110 isanother base of another plasmonic nanoparticle. See FIG. 8, infra. In anembodiment of the plasmonic apparatus, the another base of the anotherplasmonic nanoparticle has a shape at least substantially similar to ashape of the base 122 of the plasmonic nanoparticle 120. In anembodiment of the plasmonic apparatus 100, the another base of theanother plasmonic nanoparticle has a shape that overlaps a shape of thebase of the plasmonic nanoparticle. For example, the base of the anotherplasmonic nanoparticle may have a larger surface area than the base ofthe plasmonic nanoparticle.

FIGS. 1 and 2 illustrate another embodiment of the plasmonic apparatus100. The plasmonic apparatus includes the substrate 110 having the firstnegative-permittivity layer 112 comprising the first plasmonic surface114. The plasmonic apparatus includes the plasmonic nanoparticle 120having a base 122 with the second negative-permittivity layer 124comprising the second plasmonic surface 126. The plasmonic apparatusincludes the dielectric-filled gap 130 between the first plasmonicsurface and the second plasmonic surface. A plasmonic cavity 142 createdby an assembly 140 of the first plasmonic surface, the second plasmonicsurface, and the dielectric-filed gap, and having a spectrally separatedfirst fundamental resonant cavity wavelength λ₁ and second resonantcavity wavelength λ₂ that is a 3^(rd) harmonic of the first fundamentalresonant cavity wavelength λ₁. The plasmonic apparatus includes theplurality of fluorescent particles 150 located in the dielectric-filledgap. Each fluorescent particle of the plurality of fluorescent particleshas an absorption spectrum including the first fundamental resonantcavity wavelength λ₁ and a 3^(rd) harmonic nonlinearity with an emissionspectrum including the second resonant cavity wavelength λ₂.

In an embodiment of the plasmonic apparatus 100, each fluorescentparticle of the plurality of fluorescent particles 150 has an absorptionpeak at a wavelength substantially aligned with the first fundamentalresonant cavity wavelength λ₁ and a 3^(rd) harmonic nonlinearity with anemission peak at a wavelength substantially aligned with the secondresonant cavity wavelength λ₂.

FIG. 3 illustrates an example operational flow 200. After a startoperation, the operational flow includes a photoexcitation operation210. The photoexcitation operation includes directing a firstelectromagnetic beam that includes a first wavelength λ₁ at a plasmonicapparatus. A photoluminescence operation 220 includes emitting a secondelectromagnetic beam at a second wavelength λ₂from the plasmonicapparatus. The second electromagnetic beam has a higher quantum energylevel than the first electromagnetic beam. The plasmonic apparatuscomprising a substrate has a first negative-permittivity layercomprising a first plasmonic surface. The plasmonic apparatus comprisinga plasmonic nanoparticle having a base with a secondnegative-permittivity layer comprising a second plasmonic surface. Theplasmonic apparatus comprising a dielectric-filled gap between the firstplasmonic surface and the second plasmonic surface. A plasmonic cavitycreated by an assembly of the first plasmonic surface, the secondplasmonic surface, and the dielectric-filled gap, and having aspectrally separated first fundamental resonant cavity wavelength λ₁ andsecond fundamental resonant cavity wavelength λ₂. The plasmonicapparatus comprising a plurality of fluorescent particles located in thedielectric-filled gap. Each fluorescent particle of the plurality offluorescent particles has an absorption spectrum including the firstfundamental resonant cavity wavelength λ₁ and an emission spectrumincluding the second fundamental resonant cavity wavelength λ₂. Theoperational flow includes an end operation.

FIG. 4 illustrates an example gain system 300. The gain system includesa gain medium 302. The gain medium includes a plurality of plasmonicapparatus 305. Each plasmonic apparatus of the plurality of plasmonicapparatus includes a substrate having a first negative-permittivitylayer comprising a first plasmonic surface and an associated at leastone plasmonic nanoparticle having a base with a secondnegative-permittivity layer comprising a second plasmonic surface. FIG.4 illustrates a configuration of the plasmonic apparatus with aplurality of plasmonic nanoparticles 320A, 320B, and 320C in aspaced-apart linear arrangement relative to a single substrate 310having a first negative-permittivity layer 312 comprising a firstplasmonic surface 314. While the plurality of plasmonic nanoparticles isillustrated in a spaced-apart linear arrangement, they may be arrangedin any manner on the substrate, for example in a grid format. In anotherembodiment, a configuration of the plasmonic apparatus may include asingle plasmonic surface and a single plasmonic nanoparticle. In anembodiment, the plurality of plasmonic apparatus are suspended in,carried by, or incorporated into the gain medium. The gain systemincludes the plurality of plasmonic apparatus. Each plasmonic apparatusof the plurality of plasmonic apparatus includes a substrate 310 havinga first negative-permittivity layer 312 comprising a first plasmonicsurface 314.

While each plasmonic apparatus 305 may be associated with an individualsubstrate, FIG. 4 illustrates the substrate 310 having a firstnegative-permittivity layer 312 comprising a first plasmonic surface314. Each plasmonic apparatus of the plurality of plasmonic apparatusfurther includes the plurality of plasmonic nanoparticles 305 eachhaving a base with a second negative-permittivity layer comprising asecond plasmonic surface, illustrated by plasmonic nanoparticle 320Bhaving a base 322B with a second negative-permittivity layer 324Bcomprising a second plasmonic surface 326B. Each plasmonic apparatus ofthe plurality of plasmonic apparatus includes a dielectric-filled gap330 between the first plasmonic surface and the second plasmonicsurface. A plasmonic cavity 342 created by an assembly 340 of the firstplasmonic surface, the second plasmonic surface, and thedielectric-filed gap, and having a spectrally separated firstfundamental resonant cavity wavelength λ₁ and second fundamentalresonant cavity wavelength λ₂. Each plasmonic apparatus of the pluralityof plasmonic apparatus includes a plurality of fluorescent particles 350located in the dielectric-filled gap. Each fluorescent particle of theplurality of fluorescent particles has an absorption spectrum includingthe first fundamental resonant cavity wavelength λ₁ and an emissionspectrum including the second fundamental resonant cavity wavelength λ₂.An application to the gain medium of an electron pumping excitation atthe first fundamental resonant cavity wavelength λ₁ produces anamplified electromagnetic wave emission from the gain medium at thesecond fundamental resonant cavity wavelength λ₂. In an embodiment, theamplified electromagnetic wave emission includes emittingelectromagnetic waves or photons at the second fundamental resonantcavity wavelength λ₂ having a higher energy level than the appliedelectromagnetic waves or photons at first fundamental resonant cavitywavelength λ₁. In an embodiment, a photoexcitation of the gain medium ofat the first fundamental resonant cavity wavelength λ₁ producesphotoluminescence from the gain medium at the second fundamentalresonant cavity wavelength λ₂. In an embodiment, the gain systemincludes a plasmonic laser system producing a surface plasmonamplification by stimulated emission of radiation. For example, theamplified electromagnetic wave emission may include an amplified visiblelight emission. For example, the amplified electromagnetic wave emissionmay include an amplified ultraviolet light emission. For example, theamplified light emission may include an amplified infrared lightemission.

In an embodiment of the gain system 300, the amplified electromagneticwave emission includes an amplified propagating electromagnetic wave. Inan embodiment, the amplified electromagnetic wave emission includes anamplified plasmonic radiation. For example, the amplified plasmonicradiation may propagate along a guide, trace, or pathway on the firstplasmonic surface 314. In an embodiment, the amplified electromagneticwave emission includes an amplified visible light emission. In anembodiment, the amplified electromagnetic wave emission includes anamplified ultraviolet light emission. In an embodiment, the amplifiedelectromagnetic wave emission includes an amplified infrared lightemission.

In an embodiment, the gain medium 302 includes a laser gain medium. Inan embodiment, the gain system 300 includes an electron pumpingapparatus configured to excite the gain medium at the first fundamentalresonant cavity wavelength λ₁. In an embodiment, the electron pumpingapparatus includes an optical pumping apparatus. For example, an opticalpumping system may include a flash lamp, arc lamp, dischargesemiconductors, or laser. In an embodiment, the electron pumpingapparatus includes an electrical current pumping apparatus. For example,an electrical current pumping apparatus may include semiconductors, orgases via high voltage discharges.

FIG. 5 illustrates an example operational flow 400 for amplifyingelectromagnetic waves. After a start operation, the operational flowincludes a photoexcitation operation 410. The photoexcitation operationincludes applying to a gain medium an electron pumping excitation at afirst fundamental resonant cavity wavelength λ₁ of the gain medium. Theoperational flow includes a photoluminescence operation 420 emittingfrom the gain medium amplified electromagnetic waves at a secondfundamental resonant cavity wavelength λ₂ of the gain medium. The gainmedium includes a plurality of plasmonic apparatus 430. Each plasmonicapparatus of the plurality of plasmonic apparatus includes a substratehas a first negative-permittivity layer comprising a first plasmonicsurface. Each plasmonic apparatus includes a plasmonic nanoparticle hasa base with a second negative-permittivity layer comprising a secondplasmonic surface. Each plasmonic apparatus includes a dielectric-filledgap between the first plasmonic surface and the second plasmonicsurface. A plasmonic cavity created by an assembly of the firstplasmonic surface, the second plasmonic surface, and thedielectric-filled gap, and having a spectrally separated firstfundamental resonant cavity wavelength λ₁and second fundamental resonantcavity wavelength λ₂. Each plasmonic apparatus includes a plurality offluorescent particles located in the dielectric-filled gap. Eachfluorescent particle of the plurality of fluorescent particles has anabsorption spectrum including the first fundamental resonant cavitywavelength λ₁ and an emission spectrum including the second fundamentalresonant cavity wavelength λ₂. The application to the gain medium of theelectron pumping excitation at the first fundamental resonant cavitywavelength λ₁ produces an amplified electromagnetic wave emission fromthe gain medium at the second fundamental resonant cavity wavelength λ₂.In an embodiment, the amplified electromagnetic wave emission includesan amplified propagating electromagnetic wave. In an embodiment, theamplified electromagnetic wave emission includes an amplified plasmonicradiation. In an embodiment, the amplified electromagnetic wave emissionincludes an amplified visible light emission. In an embodiment, theamplified electromagnetic wave emission includes an amplifiedultraviolet light emission. In an embodiment, the amplifiedelectromagnetic wave emission includes an amplified infrared lightemission. The operational flow includes an end operation.

FIG. 6 illustrates an example plasmonic nanoparticle dimer 505. Theplasmonic dimer includes a first plasmonic nanoparticle 520.1 having abase 522.1 with a second negative-permittivity layer 524.1 comprising asecond plasmonic surface 526.1. The plasmonic dimer includes a secondplasmonic nanoparticle 520.2 having a base 522.2 with a secondnegative-permittivity layer 524.2 comprising a second plasmonic surface526.2. The plasmonic dimer includes a dielectric-filled gap 530 betweenthe first plasmonic outer surface and the second plasmonic outersurface. A plasmonic cavity 542 created by an assembly 540 of the firstplasmonic surface, the second plasmonic surface, and thedielectric-filled gap, and having a spectrally separated firstfundamental resonant cavity wavelength λ₁ and second fundamentalresonant cavity wavelength λ₂. The plasmonic dimer includes a pluralityof fluorescent particles 550 located in the dielectric-filled gap. Eachfluorescent particle of the plurality of fluorescent particles has anabsorption spectrum including the first fundamental resonant cavitywavelength λ₁ and an emission spectrum including the second fundamentalresonant cavity wavelength λ₂.

In an embodiment of the plasmonic nanoparticle dimer 505, the firstfundamental resonant cavity wavelength λ₁ is a function of a firstcharacteristic of the first plasmonic nanoparticle 520.1 and a firstcharacteristic of the second plasmonic nanoparticle 520.2. The secondfundamental resonant cavity wavelength λ₂is a function of a secondcharacteristic of the first plasmonic nanoparticle and a secondcharacteristic of the second nanoparticle. In an embodiment, the firstfundamental resonant cavity wavelength λ₁ is a function of a firststructural characteristic of the first plasmonic nanoparticle and afirst structural characteristic of the second plasmonic nanoparticle,and the second fundamental resonant cavity wavelength λ₂ is a functionof a second structural characteristic of the first plasmonicnanoparticle and a second structural characteristic of the secondnanoparticle. In an embodiment, the first fundamental resonant cavitywavelength λ₁ is a function of a first dimensional characteristic of thefirst plasmonic nanoparticle and a first dimensional characteristic ofthe second plasmonic nanoparticle. The second fundamental resonantcavity wavelength λ₂is a function of a second dimensional characteristicof the first plasmonic nanoparticle and a second dimensionalcharacteristic of the second nanoparticle. In an embodiment, the firstfundamental resonant cavity wavelength λ₁ is a function of a first sidedimension of a non-square rectangular base of the first plasmonicnanoparticle and a first side dimension of a non-square rectangular baseof the second plasmonic nanoparticle. The second fundamental resonantcavity wavelength λ₂is a function of a second side dimension of thenon-square rectangular base of the first of the first plasmonicnanoparticle and a second side dimension of the non-square rectangularbase of the second nanoparticle.

In an embodiment of the plasmonic nanoparticle dimer 505, the firstnegative-permittivity layer 524.1 includes a metallic layer. In anembodiment of the plasmonic nanoparticle dimer, the secondnegative-permittivity layer 524.2 includes a metallic layer.

In an embodiment of the plasmonic nanoparticle dimer 505, thedielectric-filled gap 530 includes a non-electrically conductivedielectric-filled gap. In an embodiment, the dielectric-filled gapincludes a dielectric film or dielectric coating applied to the firstplasmonic nanoparticle. In an embodiment, the dielectric-filled gapincludes at least one dielectric element projecting outward from thefirst plasmonic outer surface. In an embodiment, the dielectric-filledgap includes a dielectric spacer element coupled with the firstplasmonic outer surface. In an embodiment, the dielectric-filled gapincludes a dielectric-filled gap separating the first plasmonic outersurface from the second plasmonic outer surface. In an embodiment, thedielectric-filled gap is configured to establish or maintain a selecteddielectric-filled gap between the first plasmonic outer surface and thesecond plasmonic outer surface. In an embodiment, the dielectric-filledgap is configured to establish or maintain a dielectric-filled gapbetween the first plasmonic outer surface and the second plasmonic outersurface. In an embodiment, the dielectric-filled gap is configured toestablish a minimum dielectric-filled gap between the first plasmonicouter surface and the second plasmonic outer surface. In an embodiment,the dielectric-filled gap is less than a maximum chord length of thefirst plasmonic nanoparticle. In an embodiment, the dielectric-filledgap is less than about 10 percent of the maximum chord length of thefirst plasmonic nanoparticle. In an embodiment, the dielectric-filledgap is greater than about 0.05 percent of the maximum chord length ofthe first plasmonic nanoparticle. In an embodiment, thedielectric-filled gap has a thickness 532 of less than about 50 nm. Inan embodiment, the dielectric-filled gap has a thickness less than about20 nm. In an embodiment, the dielectric-filled gap has a thickness ofless than about 10 nm.

In an embodiment, a gas, fluid, or solid gain medium 560 carries theplasmonic nanoparticle dimer 505. In an embodiment, a gas, fluid, orsolid colloid gain medium carries the plasmonic nanoparticle dimer.

FIG. 7 illustrates an environment 600 that includes an electromagneticwave gain system 605. The gain system includes a dispersion 610 of aplurality of plasmonic nanoparticle dimers 605 in a gain medium 660. Inan embodiment, at least one dimer of the plurality plasmonicnanoparticle dimers 605 is substantially similar to the plasmonicnanoparticle dimer 505 described in conjunction with FIG. 6. Using theplasmonic nanoparticle dimer 505 to illustrate the plasmonicnanoparticle dimers 605, the plasmonic dimer includes a first plasmonicnanoparticle 520.1 having a base 522.1 with a secondnegative-permittivity layer 524.1 comprising a second plasmonic surface526.1. The plasmonic dimer includes a second plasmonic nanoparticle520.2 having a base 522.2 with a second negative-permittivity layer524.2 comprising a second plasmonic surface 526.2. The plasmonic dimerincludes a dielectric-filled gap 530 between the first plasmonic outersurface and the second plasmonic outer surface. A plasmonic cavity 542created by an assembly 540 of the first plasmonic surface, the secondplasmonic surface, and the dielectric-filled gap, and having aspectrally separated first fundamental resonant cavity wavelength λ₁andsecond fundamental resonant cavity wavelength λ₂. The plasmonic dimerincludes a plurality of fluorescent particles 550 located in thedielectric-filled gap. Each fluorescent particle of the plurality offluorescent particles has an absorption spectrum including the firstfundamental resonant cavity wavelength λ₁ and an emission spectrumincluding the second fundamental resonant cavity wavelength λ₂. The gainsystem includes a gain medium 670. An application to the gain medium ofan electron pumping excitation at the first fundamental resonant cavitywavelength λ₁ produces an amplified electromagnetic wave emission fromthe gain medium at the second fundamental resonant cavity wavelength λ₂.In an embodiment, the amplified electromagnetic wave emission includesan amplified propagating electromagnetic wave. In an embodiment, theamplified electromagnetic wave emission includes an amplified plasmonicradiation. In an embodiment, the amplified electromagnetic wave emissionincludes an amplified visible light emission. In an embodiment, theamplified electromagnetic wave emission includes an amplifiedultraviolet light emission. In an embodiment, the amplifiedelectromagnetic wave emission includes an amplified infrared lightemission.

In an embodiment, the gain medium 670 includes a colloid mixture. In anembodiment, the gain medium includes a fluid. In an embodiment, the gainmedium includes a solid. In an embodiment, the gain medium includes agas. In an embodiment, the gain system 605 includes a containerconfigured to hold the gain medium. In an embodiment, the gain systemincludes an electron pumping apparatus 680 configured to excite the gainmedium at the first fundamental resonant cavity wavelength λ₁. In anembodiment, the electron pumping apparatus includes an optical pumpingapparatus.

FIG. 8 illustrates an example operational flow 700. After a startoperation, the operational flow includes a photoexcitation operation710. The photoexcitation operation includes applying to a gain medium anelectron pumping excitation at a first fundamental resonant cavitywavelength λ₁ of the gain medium. In an embodiment, the photoexcitationoperation may be implemented using the electron pumping apparatus 680 toexcite the gain system 605 described in conjunction with FIG. 7. Theoperational flow includes a photoluminescence operation 720 emittingfrom the gain medium amplified electromagnetic waves at a secondfundamental resonant cavity wavelength λ₂ of the gain medium. The gainmedium includes a plurality of plasmonic nanoparticle dimers 730. Eachplasmonic nanoparticle dimer of the plurality of plasmonic nanoparticledimers includes a first plasmonic nanoparticle having a base with asecond negative-permittivity layer comprising a second plasmonicsurface. Each plasmonic nanoparticle dimer of the plurality of plasmonicnanoparticle dimers includes a second plasmonic nanoparticle having abase with a second negative-permittivity layer comprising a secondplasmonic surface. Each plasmonic nanoparticle dimer of the plurality ofplasmonic nanoparticle dimers includes dielectric-filled gap between thefirst plasmonic outer surface and the second plasmonic outer surface. Aplasmonic cavity created by an assembly of the first plasmonic surface,the second plasmonic surface, and the dielectric-filled gap, and havinga spectrally separated first fundamental resonant cavity wavelength λ₁and second fundamental resonant cavity wavelength λ₂. Each plasmonicnanoparticle dimer of the plurality of plasmonic nanoparticle dimersincludes a plurality of fluorescent particles located in thedielectric-filled gap. Each fluorescent particle of the plurality offluorescent particles has an absorption spectrum including the firstfundamental resonant cavity wavelength λ₁ and an emission spectrumincluding the second fundamental resonant cavity wavelength λ₂, whereinthe application to the gain medium of the electron pumping excitation atthe first fundamental resonant cavity wavelength λ₁ produces anamplified electromagnetic wave emission from the gain medium at thesecond fundamental resonant cavity wavelength λ₂. The operational flowincludes an end operation.

All references cited herein are hereby incorporated by reference intheir entirety or to the extent their subject matter is not otherwiseinconsistent herewith.

In some embodiments, “configured” or “ configured to” includes at leastone of designed, set up, shaped, implemented, constructed, or adaptedfor at least one of a particular purpose, application, or function. Insome embodiments, “configured” or “configured to” includes positioned,oriented, or structured for at least one of a particular purpose,application, or function.

It will be understood that, in general, terms used herein, andespecially in the appended claims, are generally intended as “open”terms. For example, the term “including” should be interpreted as“including but not limited to.” For example, the term “having” or “has”should be interpreted as “having at least.” For example, the term “has”should be interpreted as “having at least.” For example, the term“includes” should be interpreted as “includes but is not limited to,”etc. It will be further understood that if a specific number of anintroduced claim recitation is intended, such an intent will beexplicitly recited in the claim, and in the absence of such recitationno such intent is present. For example, as an aid to understanding, thefollowing appended claims may contain usage of introductory phrases suchas “at least one” or “one or more” to introduce claim recitations.However, the use of such phrases should not be construed to imply thatthe introduction of a claim recitation by the indefinite articles “a” or“an” limits any particular claim containing such introduced claimrecitation to inventions containing only one such recitation, even whenthe same claim includes the introductory phrases “one or more” or “atleast one” and indefinite articles such as “a” or “an” (e.g., “areceiver” should typically be interpreted to mean “at least onereceiver”); the same holds true for the use of definite articles used tointroduce claim recitations. In addition, even if a specific number ofan introduced claim recitation is explicitly recited, it will berecognized that such recitation should typically be interpreted to meanat least the recited number (e.g., the bare recitation of “at least twochambers,” or “a plurality of chambers,” without other modifiers,typically means at least two chambers).

In those instances where a phrase such as “at least one of A, B, and C,”“at least one of A, B, or C,” or “an [item] selected from the groupconsisting of A, B, and C,” is used, in general such a construction isintended to be disjunctive (e.g., any of these phrases would include butnot be limited to systems that have A alone, B alone, C alone, A and Btogether, A and C together, B and C together, or A, B, and C together,and may further include more than one of A, B, or C, such as A₁, A₂, andC together, A, B₁, B₂, C₁, and C₂ together, or B₁ and B₂ together). Itwill be further understood that virtually any disjunctive word or phrasepresenting two or more alternative terms, whether in the description,claims, or drawings, should be understood to contemplate thepossibilities of including one of the terms, either of the terms, orboth terms. For example, the phrase “A or B” will be understood toinclude the possibilities of “A” or “B” or “A and B.”

The herein described aspects depict different components containedwithin, or connected with, different other components. It is to beunderstood that such depicted architectures are merely examples, andthat in fact many other architectures can be implemented which achievethe same functionality. In a conceptual sense, any arrangement ofcomponents to achieve the same functionality is effectively “associated”such that the desired functionality is achieved. Hence, any twocomponents herein combined to achieve a particular functionality can beseen as “associated with” each other such that the desired functionalityis achieved, irrespective of architectures or intermedial components.Likewise, any two components so associated can also be viewed as being“operably connected,” or “operably coupled,” to each other to achievethe desired functionality. Any two components capable of being soassociated can also be viewed as being “operably couplable” to eachother to achieve the desired functionality. Specific examples ofoperably couplable include but are not limited to physically mateable orphysically interacting components or wirelessly interactable orwirelessly interacting components.

With respect to the appended claims the recited operations therein maygenerally be performed in any order. Also, although various operationalflows are presented in a sequence(s), it should be understood that thevarious operations may be performed in other orders than those which areillustrated, or may be performed concurrently. Examples of suchalternate orderings may include overlapping, interleaved, interrupted,reordered, incremental, preparatory, supplemental, simultaneous,reverse, or other variant orderings, unless context dictates otherwise.Use of “Start,” “End,” “Stop,” or the like blocks in the block diagramsis not intended to indicate a limitation on the beginning or end of anyoperations or functions in the diagram. Such flowcharts or diagrams maybe incorporated into other flowcharts or diagrams where additionalfunctions are performed before or after the functions shown in thediagrams of this application. Furthermore, terms like “responsive to,”“related to,” or other past-tense adjectives are generally not intendedto exclude such variants, unless context dictates otherwise.

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments will be apparent to those skilled in the art.The various aspects and embodiments disclosed herein are for purposes ofillustration and are not intended to be limiting, with the true scopeand spirit being indicated by the following claims.

What is claimed is:
 1. A plasmonic apparatus comprising: a substratehaving a first negative-permittivity layer comprising a first plasmonicsurface; a plasmonic nanoparticle having a base with a secondnegative-permittivity layer comprising a second plasmonic surface; adielectric-filled gap between the first plasmonic surface and the secondplasmonic surface; a plasmonic cavity created by an assembly of thefirst plasmonic surface, the second plasmonic surface, and thedielectric-filled gap, and having a spectrally separated firstfundamental resonant cavity wavelength λ₁ and second fundamentalresonant cavity wavelength λ₂; and a plurality of fluorescent particleslocated in the dielectric-filled gap, each fluorescent particle of theplurality of fluorescent particles having an absorption spectrumincluding the first fundamental resonant cavity wavelength λ₁ and anemission spectrum including the second fundamental resonant cavitywavelength λ₂.
 2. The plasmonic apparatus of claim 1, wherein the firstfundamental resonant cavity wavelength λ₁ is a function of a firstcharacteristic of the plasmonic nanoparticle and the second fundamentalresonant cavity wavelength λ₂ is a function of a second characteristicof the plasmonic nanoparticle.
 3. The plasmonic apparatus of claim 2,wherein the first fundamental resonant cavity wavelength λ₁ is afunction of a first structural characteristic of the plasmonicnanoparticle and the second fundamental resonant cavity wavelength λ₂ isa function of a second structural characteristic of the plasmonicnanoparticle.
 4. The plasmonic apparatus of claim 2, wherein the firstfundamental resonant cavity wavelength λ₁ is a function of a firstdimensional characteristic of the plasmonic nanoparticle and the secondfundamental resonant cavity wavelength λ₂ is a function of a seconddimensional characteristic of the plasmonic nanoparticle.
 5. Theplasmonic apparatus of claim 1, wherein the first fundamental resonantcavity wavelength λ₁ is a function of a first side dimension of anon-square rectangular base of the plasmonic nanoparticle and the secondfundamental resonant cavity wavelength λ₂ is a function of a second sidedimension of the non-square rectangular base of the plasmonicnanoparticle.
 6. The plasmonic apparatus of claim 1, wherein the base ofthe plasmonic nanoparticle is conformal to the first plasmonic surface.7. (canceled)
 8. The plasmonic apparatus of claim 1, wherein the base ofthe plasmonic nanoparticle has a major side, and a minor side shorterthan the major side.
 9. (canceled)
 10. (canceled)
 11. The plasmonicapparatus of claim 1, wherein the plasmonic nanoparticle includes atleast two joined or proximate plasmonic nanoparticles forming incombination the base with a second negative-permittivity layercomprising a second plasmonic surface.
 12. (canceled)
 13. The plasmonicapparatus of claim 1, wherein the plasmonic nanoparticle includes ananorod having a non-square rectangular base with the secondnegative-permittivity layer.
 14. (canceled)
 15. (canceled)
 16. Theplasmonic apparatus of claim 1, wherein the base of the plasmonicnanoparticle has an arbitrary shape.
 17. The plasmonic apparatus ofclaim 1, wherein the base of the plasmonic nanoparticle has a major sidelength ranging between 10-10000 nm.
 18. The plasmonic apparatus of claim1, wherein the base of the plasmonic nanoparticle has a major sidelength between about 100 and about 1000 nm.
 19. (canceled)
 20. Theplasmonic apparatus of claim 1, wherein the plasmonic cavity has aspectrally separated first spectral resonant envelope that includes thefirst fundamental resonant wavelength λ₁ and a second spectral resonantenvelope that includes the second fundamental resonant wavelength λ₂.21. (canceled)
 22. (canceled)
 23. The plasmonic apparatus of claim 1,wherein the first fundamental resonant wavelength λ₁ is in theultraviolet spectrum and second fundamental resonant wavelength λ₂ ofthe plasmonic cavity is in the visible light spectrum.
 24. (canceled)25. The plasmonic apparatus of claim 1, wherein the first fundamentalresonant wavelength λ₁ and second fundamental resonant wavelength λ₂ ofthe plasmonic cavity are both in the visible light spectrum. 26.(canceled)
 27. (canceled)
 28. The plasmonic apparatus of claim 1,wherein the second fundamental resonant cavity wavelength λ₂ of theplasmonic nanoparticle is a harmonic of the first fundamental resonantcavity wavelength λ₁ of the plasmonic cavity.
 29. (canceled) 30.(canceled)
 31. The plasmonic apparatus of claim 1, wherein (i) thesecond fundamental resonant cavity wavelength λ₂ is a 3^(rd) harmonic ofthe first fundamental resonant cavity wavelength λ₁ of the plasmoniccavity; and (ii) each fluorescent particle of the plurality offluorescent particles includes a fluorescent particle with a 3^(rd)harmonic nonlinearity having an emission spectrum including the secondfundamental resonant cavity wavelength λ₂.
 32. The plasmonic apparatusof claim 1, wherein the dielectric includes a non-linear opticalmaterial having a non-linear response configured to enhance emission atthe second fundamental resonant cavity wavelength λ₂.
 33. The plasmonicapparatus of claim 1, wherein the plasmonic nanoparticle includes aplurality of plasmonic nanoparticles, each plasmonic nanoparticle of theplurality of plasmonic nanoparticles having a base with a secondnegative-permittivity layer comprising in combination a second plasmonicsurface.
 34. The plasmonic apparatus of claim 1, wherein the plasmonicnanoparticle includes a doubly-resonant plasmonic nanoparticle.
 35. Theplasmonic apparatus of claim 1, wherein at least one of the plasmonicnanoparticle, the substrate, or the dielectric includes a nonlinearharmonic material.
 36. (canceled)
 37. The plasmonic apparatus of claim1, wherein the first plasmonic surface is coated with at least twofluorescent particles of the plurality of fluorescent particles.
 38. Theplasmonic apparatus of claim 1, wherein the second plasmonic surface iscoated with at least two fluorescent particles of the plurality offluorescent particles.
 39. The plasmonic apparatus of claim 1, whereinthe plurality of fluorescent particles are included in thedielectric-filled gap.
 40. (canceled)
 41. (canceled)
 42. The plasmonicapparatus of claim 1, wherein the first plasmonic surface includes anadhesive configured to bond the first plasmonic surface with adielectric material of the dielectric-filled gap.
 43. The plasmonicapparatus of claim 1, wherein the first negative-permittivity layer hasnegative permittivity within a defined wavelength range.
 44. (canceled)45. The plasmonic apparatus of claim 1, wherein the firstnegative-permittivity layer includes a metallic layer.
 46. The plasmonicapparatus of claim 1, wherein the first negative-permittivity layerincludes a semi-metallic layer.
 47. The plasmonic apparatus of claim 1,wherein the first negative-permittivity layer includes a semiconductorlayer. 48-51. (canceled)
 52. The plasmonic apparatus of claim 1, whereinthe second negative-permittivity layer includes a metallic layer. 53.The plasmonic apparatus of claim 1, wherein the secondnegative-permittivity layer includes a semimetal layer.
 54. Theplasmonic apparatus of claim 1, wherein the second negative-permittivitylayer includes a semiconductor layer or a polaritonic dielectric layer.55. (canceled)
 56. The plasmonic apparatus of claim 1, wherein at leasta portion of the dielectric-filled gap comprises a dielectric coatingapplied to the first plasmonic surface of the substrate.
 57. Theplasmonic apparatus of claim 1, wherein at least a portion of thedielectric-filled gap comprises a dielectric coating applied to thesecond plasmonic surface of the plasmonic nanoparticle.
 58. Theplasmonic apparatus of claim 1, wherein the dielectric-filled gap isless than 5 nm thick.
 59. The plasmonic apparatus of claim 1, whereinthe dielectric-filled gap is less than 100 nm thick. 60-63. (canceled)60. The plasmonic apparatus of claim 1, wherein the dielectric-filledgap is less than 50 nm thick.
 61. The plasmonic apparatus of claim 1,wherein the dielectric-filled gap is less than 25 nm.
 62. The plasmonicapparatus of claim 1, wherein the dielectric-filled gap is greater than0 nm and less than 50 nm.
 63. The plasmonic apparatus of claim 1,wherein the dielectric-filled gap is greater than 5 nm.
 64. (canceled)65. The plasmonic apparatus of claim 1, wherein each fluorescentparticle of the plurality of fluorescent particles has an absorptionpeak at a wavelength aligned with the first fundamental resonant cavitywavelength λ₁ and an emission peak substantially aligned with the secondfundamental resonant cavity wavelength λ₂. 66-71. (canceled)
 72. Theplasmonic apparatus of claim 1, wherein the substrate is a base of asecond plasmonic nanoparticle.
 73. (canceled)
 74. (canceled)
 75. Aplasmonic apparatus comprising: a substrate having a firstnegative-permittivity layer comprising a first plasmonic surface; aplasmonic nanoparticle having a base with a second negative-permittivitylayer comprising a second plasmonic surface; a dielectric-filled gapbetween the first plasmonic surface and the second plasmonic surface, aplasmonic cavity created by an assembly of the first plasmonic surface,the second plasmonic surface, and the dielectric-filed gap, and having aspectrally separated first fundamental resonant cavity wavelength λ₁ andsecond resonant cavity wavelength λ₂ that is a 3^(rd) harmonic of thefirst fundamental resonant cavity wavelength λ₁; and a plurality offluorescent particles located in the dielectric-filled gap, eachfluorescent particle of the plurality of fluorescent particles having anabsorption spectrum including the first fundamental resonant cavitywavelength λ₁ and a 3^(rd) harmonic nonlinearity with an emissionspectrum including the second resonant cavity wavelength λ₂.
 76. Theplasmonic apparatus of claim 75, wherein each fluorescent particle ofthe plurality of fluorescent particles has an absorption peak at awavelength substantially aligned with the first fundamental resonantcavity wavelength λ₁ and a 3^(rd) harmonic nonlinearity with an emissionpeak at a wavelength substantially aligned with the second resonantcavity wavelength λ₂.
 77. (canceled)
 78. (canceled)
 79. A methodcomprising: directing a first electromagnetic beam that includes a firstwavelength λ₁ at a plasmonic apparatus; and emitting a secondelectromagnetic beam at a second wavelength λ₂ from the plasmonicapparatus, the second electromagnetic beam having a higher quantumenergy level than the first electromagnetic beam, the plasmonicapparatus comprising: a substrate having a first negative-permittivitylayer comprising a first plasmonic surface; a plasmonic nanoparticlehaving a base with a second negative-permittivity layer comprising asecond plasmonic surface; a dielectric-filled gap between the firstplasmonic surface and the second plasmonic surface; a plasmonic cavitycreated by an assembly of the first plasmonic surface, the secondplasmonic surface, and the dielectric-filled gap, and having aspectrally separated first fundamental resonant cavity wavelength λ₁ andsecond fundamental resonant cavity wavelength λ₂; and a plurality offluorescent particles located in the dielectric-filled gap, eachfluorescent particle of the plurality of fluorescent particles having anabsorption spectrum including the first fundamental resonant cavitywavelength λ₁ and an emission spectrum including the second fundamentalresonant cavity wavelength λ₂.
 80. The method of claim 79, wherein thesecond electromagnetic beam has at least a 10× higher quantum energylevel than the first electromagnetic beam.
 81. The method of claim 79,wherein the second electromagnetic beam has at least a 100× higherquantum energy level than the first electromagnetic beam.
 82. (canceled)83. (canceled)
 84. (canceled)